Hi Maria,
I'd like to confirm the following information to troubleshoot the issue:
1. Can you specify "navigating between subsites and document libraries within sharepoint"? Can you share a screenshot?
2. Which browser were you using? Can you try using another latest version of browser such as IE, Chrome to see if the issue persists?
3. Did you try using the "Private Browsing" mode to see if it helps?
4. Have you added the problematic site to trust sites in IE?
5. Did you organization members encounter the same issue?
6. Can you switch another network environment to see if it helps?
To upload screenshots, please click Use rich Formatting in this thread and select the Insert/Edit Media icon.
Please post back at your convenience and we will follow up on the case.Thanks for your time.
Regards,
Alice Wang